Location system

ABSTRACT

A location system comprises a communication terminal for transmitting a location request specifying a target mobile terminal and a type of location information, and a location network. In response to the location request, the location network produces current location information of the target mobile terminal if the type of location information of the received request specifies current location information and transmits the current location information to the communication terminal and stores the last known location information in a memory as last known location information of the target mobile terminal. If the type of location information specifies last known location information, stored last known location information of the target mobile terminal is copied from the memory and transmitted to the communication terminal if the location request is verified by a privacy check and if the stored information is reusable.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to location systems forproviding information services to clients as to the location of mobileuser equipment (UE) terminals according to the 3GPP (Third GenerationPartnership Program) Technical Specification 23.271 v. 5.3.0,“Functional stage 2 description of LCS”, pages 33-62, June 2002. Morespecifically, the present invention is concerned with the reuse of lastknown location information.

[0003] 2. Description of the Related Art

[0004] The location information of a mobile UE terminal is usuallysensitive to the privacy of the mobile user and often crucial when theuser is in a critical situation. To protect mobile users from illegalaccess to their private location information, the mobile communicationsnetwork is provided with a sophisticated privacy protection mechanismwhich imposes various restrictions on location requests according toprivacy profiles (time and place) specified by the mobile users. Theprivacy protection mechanism provides two types of verification on alocation request according to decision capability that varies with apoint in the network where the location request is being served. Thefirst type of verification is performed on a client terminal when thenetwork receives a location request from this terminal, known as clientcheck. The second type of verification is a permission granted to thelocation request after location information of a UE terminal has beenobtained if the place and time interval specified by the privacy profileof the UE terminal user are satisfied, known as privacy check.

[0005] Mobile network providers, on the other hand, are required toprovide location service in addition to their basic mobilecommunications service. Specifically, the location service involvesseveral network nodes exchanging special messages with one another forthe position calculation of a target UE and exchanging messages with atarget UE terminal over wireless link.

[0006] The 3GPP location information system, as specified in the 3GPPstandard, is basically made up of client terminal, GMLC (Gateway MobileLocation Center), SGSN/MSC (Serving General packet radio service SupportNode/Mobile Services switching Center), local wireless network known asRAN (Radio Access Network) and UE (User Equipment) terminal connected tothe RAN via wireless link. HLR/HSS (Home Location Register/HomeSubscriber Server) is connected to the GMLC as a database for holdingthe identity of the RAN to which UE terminals are connected. Registeredclient terminals are given exclusive right to access UE terminals.

[0007] The 3GPP standard provides two modes of operation for requestinglocation information, i.e., the mobile terminated location request(MT-LR) and the mobile originated location request (MO-LR). In the MT-LRmode, the client terminal can either request the current location of atarget UE or the current or last known location of this terminal. Thelast known location information is used as a location report instead ofthe current location information when the network has failed in locatingthe target UE for some reason if the last known location information isusable.

[0008] More specifically, when the network receives a location requestfor a target UE, the SGSN/MSC responsible for the management of thetarget UE is also responsible for the privacy protection of the UEterminal. According to the privacy protection of the MT-LR mode asspecified by the 3GPP standard, UE mobile users register their privacyprofile (e.g., the identifiers of those clients allowed to request theirlocation) in the SGSN/MSC of their home network. In response to alocation request, the SGSN/MSC performs a privacy check by verifying itagainst the registered privacy profile of the target UE and determineswhether or not the location request is granted. If the privacy profileof a UE terminal further specifies that a notification/verificationrequest be sent to the UE terminal, the UE terminal is given anotification that it is being targeted or verifies the location requestand returns a verification result to the client terminal. When thelocation request is acceptable, the SGSN/MSC proceeds with a locationestimation process in collaboration with the associated RAN to determinethe current location of the target UE. If the SGSN/MSC fails to acquirecurrent location information of a target UE, a copy of the stored lastknown location information of the target UE is transmitted to the clientterminal if this information is currently still usable, or significant.

[0009] In the MO-LR mode, the mobile UE terminal exclusively requestsits own current location from the network. In this mode, a failure inlocation measurement will result in the transmission of an error reportto the requesting mobile UE terminal. Last known location information isnot reused at all for transmission instead of the error report.

[0010] However, a number of shortcomings exist in the prior art locationsystem.

[0011] First, the flow of traffic through the location network and theamount of location measurement calculations increase in proportion tolocation requests from client and mobile terminals. Further, part of thelocation network is shared in common by a mobile communication network.Therefore, when the location network experiences heavy traffic loads, itis likely that mobile communication traffic is adversely affected, whichcould lead to an extra burden on mobile network providers.

[0012] Second, in the MT-LR mode of operation, privacy check isperformed by the SGSN/MSC. If reusable last known location informationof a UE terminal is available in the GMLC, for example, the SGSN/MSCwould perform privacy check for the UE terminal. However, no mechanismis provided for the GMLC to request the SGSN/MSC to perform privacycheck. As a result, privacy protection of last known locationinformation is only ensured when this private information is maintainedin the GMLC.

[0013] Third, the reusability of last known location information dependsexclusively on whether or not an SGSN/MSC is holding the last knownlocation information, and the criteria of usability depends on specificdetails of an SGSN/MSC which may differ among different SGSN/MSCs.Therefore, it is likely that requesting client terminals may receiveworthless last known location information.

SUMMARY OF THE INVENTION

[0014] It is therefore an object of the present invention to provide alocation system that reduces location traffic loads and measurementcalculation loads and concomitant elimination of an extra network cost.

[0015] It is a further object of the present invention to provide alocation system capable of utilizing last known location information ofa mobile terminal for both MT-LR (mobile terminated location request)and MO-LR (mobile originated location request) modes of operation,regardless of whether an SGSN/MSC has failed in obtaining currentlocation information of a target mobile UE (user equipment) terminal.

[0016] It is a still further object of the present invention to providea location system capable of providing privacy protection of target UEterminals when their last known location information are reused.

[0017] It is a still further object of the present invention to providea location system capable of establishing reusability criteria for lastknown location information according to requests from client terminalsas well as from UE terminals indicating an age parameter of their lastknown location information.

[0018] According to a first aspect of the present invention, there isprovided a location system for locating a plurality of mobile terminals.The system comprises a communication terminal for transmitting alocation request specifying a target mobile terminal and a type oflocation information, and a location network. The location network isresponsive to the location request from the communication terminal forproducing current location information of the target mobile terminal ifthe type of location information of the received request specifiescurrent location information and transmitting the current locationinformation to the communication terminal and storing the last knownlocation information in a memory as last known location information ofthe target mobile terminal, and copying stored last known locationinformation of the target mobile terminal from the memory if the type oflocation information specifies last known location information andtransmitting the copied information to the communication terminal.

[0019] The network performs a reusability test on the stored last knownlocation information and transmits the last known location informationif the reusability test indicates a favorable result and transmits thecurrent location information if the reusability test indicates anunfavorable result.

[0020] According to a second aspect, the present invention provides alocation method comprising the steps of transmitting a location requestfrom a communication terminal, the request specifying a target mobileterminal and a type of location information, receiving the locationrequest at a location network, producing current location information ofthe target mobile terminal and transmitting the current locationinformation from the location network to the communication terminal ifthe type of location information of the received request specifiescurrent location information, storing the current location informationin a memory as last known location information of the target mobileterminal, and copying the stored last known location information of thetarget mobile terminal from the memory if the type of locationinformation specifies last known location information and transmittingthe copied information from the location network to the communicationterminal.

[0021] According to a third aspect, the present invention provides amethod of operating a gateway with a location network. The methodcomprises the steps of receiving a location request from a communicationterminal, said request specifying a target mobile terminal and a type oflocation information, acquiring current location information of thetarget mobile terminal from said location network and transmitting thecurrent location information to said communication terminal if the typeof location information of the received request specifies currentlocation information, storing the current location information in amemory as last known location information of the target mobile terminal,and transmitting a copy of the stored last known location information ofthe target mobile terminal to said communication terminal if said typeof location information specifies last known location information.

[0022] According to a fourth aspect, the present invention provides acommunication terminal which comprises a transmit means for transmittinga location request to a location system in which last known locationinformation of mobile terminals are stored, the location requestspecifying a target mobile terminal and a type of last known locationinformation, and receive means for receiving from the location system acopy of current location information of the target mobile terminal ifthe type specifies current location information or a copy of last knownlocation information of the target mobile terminal if the type specifieslast known location information.

BRIEF DESCRIPTION OF THE DRAWIGNS

[0023] The present invention will be described in detail further withreference to the following drawings, in which:

[0024]FIG. 1 is a block diagram of a location system of the presentinvention;

[0025]FIGS. 2A and 2B are block diagrams useful for describing a firstnetwork configuration of the present invention;

[0026]FIG. 3 is a block diagram useful for describing a second networkconfiguration of the present invention;

[0027]FIG. 4 is a block diagram useful for describing a third networkconfiguration of the present invention;

[0028]FIG. 5 is a block diagram useful for describing a fourth networkconfiguration of the present invention;

[0029]FIG. 6 is a block diagram useful for describing a fifth networkconfiguration of the present invention;

[0030]FIGS. 7A and 7B are block diagrams useful for describing a sixthnetwork configuration of the present invention;

[0031]FIGS. 5A and 8B are block diagrams useful for describing a seventhnetwork configuration of the present invention;

[0032]FIGS. 9A and 9B are block diagrams useful for describing an eighthnetwork configuration of the present invention;

[0033]FIGS. 10A and 10B are block diagrams useful for describing a ninthnetwork configuration of the present invention;

[0034]FIGS. 11A and 11B are block diagrams useful for describing a tenthnetwork configuration of the present invention;

[0035]FIGS. 12A to 12E are flowcharts of the operation of a local GMLCwhich maintains the privacy information of its home UE terminals, andFIG. 12F is a flowchart of a local GMLC which does not maintain theprivacy information of its home UE terminals;

[0036]FIG. 13 is a flowchart of the operation of a SGSN/MSC of thepresent invention;

[0037]FIG. 14 is a flowchart of the operation of a mobile terminal ofthe present invention;

[0038]FIGS. 15A, 15B and 15C are sequence diagrams associated with thefirst network mode of operation of the present invention;

[0039]FIG. 16 is a sequence diagram associated with the second networkmode of operation;

[0040]FIG. 17 is a sequence diagram associated with the third networkmode of operation;

[0041]FIG. 18 is a sequence diagram associated with the fourth networkmode of operation;

[0042]FIG. 19 is a sequence diagram associated with the fifth networkmode of the present invention;

[0043]FIG. 20 is a sequence diagram associated with the sixth networkmode of the present invention;

[0044]FIG. 21 is a sequence diagram associated with the seventh networkmode of the present invention;

[0045]FIG. 22 is a sequence diagram associated with the eighth networkmode of the present invention;

[0046]FIG. 23 is a sequence diagram associated with the ninth networkmode of the present invention; and

[0047]FIG. 24 is a sequence diagram associated with the tenth networkmode of the present invention.

GENERAL DESCRIPTION

[0048] Referring now to FIG. 1, there is shown a location system of amobile multi-network in which the present invention is incorporated. Thelocation system is comprised of a plurality of client terminals 101,111, 121 connected via landline links to a location network and a mobileUE terminal 105 wirelessly connected the location network.

[0049] The location network is formed by a plurality of GMLCs (GatewayMobile Location Centers) 102, 112, 122 to which client terminals 101,111, 121 are respectively connected to send their location requests toand receive location reports from the associated GMLCs. GMLCs 102, 112,122 are connected to SGSN/MSCs (Serving General packet radio serviceSupport Node/Mobile service Switching Centers) 103, 113 and 123,respectively, and mutually connected to one another. SGSN/MSCs 103, 113,123 are respectively connected to RANs (Radio Access Networks) 104, 114,124. Further associated with the GMLCs 102, 112, 122 are HLR/HSSs (HomeLocation Register/Home Subscriber Server) 106, 116 and 125. Privacyprofile registers (PPR) 107, 117, 127 are also connected to the GMLCs102, 112, 122, respectively.

[0050] The network nodes which are directly connected to each other,such as GMLC, HLR/HSS, SGSN/MSC, RAN, PPR, form a group known as a homenetwork for mobile UE (user equipment) terminals. For example, a UEterminal 105 is connected as a home UE terminal via a wireless link tothe RAN 104.

[0051] As shown in FIG. 1, the client terminal transmits a locationrequest message 150 having a number of fields containing a message type,a source address (client's identifier), a destination address (phonenumber of target mobile UE terminal), a location information type and areusability criteria. The location information type field specifies atype of location information (C=current, L=last known, C/L=current orlast known, or L/C=last known or current). The “current or last known”type indicates that the current location information is given priorityover the last known location information if both information areavailable, and the “last known or current” type of location informationindicates that the last known location information is given priorityover the current location information if both information are available.Current location information may be a default setting. If the requestinguser desires a previous location of a target UE terminal, theinformation-type field of the message is set equal to L. If therequesting user desires a previous location of a target UE terminal, butallows current location information if the previous location is notavailable nor reusable, the message contains an information-type fieldset equal to L/C. The information-type field of the message may be setequal to C/L if the user allows last known location information ifcurrent location information is not available. The reusability criteriafield of the location request message specifies the accuracy of lastknown location information (allowable distance error) and the allowableage of last known information. The reusability criteria will be used bythe location network to make a decision as to whether stored last knownlocation information of a UE terminal can be reused.

[0052] Each mobile terminal is also capable of transmitting a locationrequest which specifies its own mobile terminal and contains a type oflocation information.

[0053] The location network stores last known location information ofthe mobile terminals. The location network is responsive to a locationrequest from the communication terminal, either from client terminal ormobile terminal, for producing current location information of a targetmobile terminal specified by the request and transmitting it to thecommunication terminal if the type of location information of thereceived request is current location information, and transmitting acopy of the stored last known location information of the target mobileterminal to the communication terminal if the type of locationinformation is last known location information.

[0054] The location network is responsive to a location request from theclient terminal for performing privacy check on the location requestprior to the transmission of said last known location information to thecommunication terminal. The location network performs reusability checkon the stored last known location information according to the privacyprofile of the target mobile terminal or client terminal.

[0055] Identification data of the SGSN/MSCs 103, 113, 123 are maintainedin the associated HLR/HSSs 106, 116, 126. The privacy profile of UEterminal 105 is stored in the GMLC of the home network, (i.e., GMLC102).

NETWORK CONFIGURATIONS

[0056] The present invention provides a number of network configurationsdepending on the location of the requesting communication terminal(client or mobile), the location of the target UE terminal 105 as wellas the location of network nodes where privacy profiles and locationreports are maintained.

First Network Configuration

[0057] The first network configuration is shown in FIGS. 2A and 2B. Theclient terminal 101 is the requesting terminal, and the target UE 105 iscurrently establishing its link to home network A.

[0058] In FIG. 2A, the privacy profile and location information of thetarget UE are maintained in the home GMLC 102. The client terminal 101includes a transmit means 1011 for transmitting a location request tothe home GMLC 102 and a receive means 1012 for receiving locationinformation from the GMLC 102. GMLC 102 includes a memory 1021 forstoring the privacy profile and last known location information of UE105, and a client/privacy check means 1022. In response to the locationrequest from the client terminal 101, the client/privacy check means1022 performs a client check on the requesting terminal.

[0059] If the client terminal fails to pass the client check, theclient/privacy check means 1022 formulates an error message and sends itfrom a report transmit means 1026 to the requesting terminal 101. If theclient terminal is verified, the client/privacy check means 1022proceeds to reference the privacy profile of the target UE stored in thememory 1021 and performs a first privacy check on the location request.If the location request fails to pass the first privacy check, an errormessage is supplied from the check means 1022 to the report transmitmeans 1026 and transmitted to the client terminal. If the locationrequest is verified by the first privacy check, the check means 1022determines which type of location information the request specifies.

[0060] If the location request specifies type C or C/L, theclient/privacy check means 1022 instructs a notification/verificationmeans 1024 to transmit a location request to the SGSN/MSC 103 to performa location estimation process with the RAN 104 to determine the locationof the target UE 105. A location report is then returned from theSGSN/MSC 103 to a second privacy check means 1025. In response to thelocation report, the second privacy check means 1025 proceeds to performa second privacy check.

[0061] If the location request specifies type L or L/C, theclient/privacy check means 1022 instructs a reusability check means 1023to make a search through the memory 1021 for last known locationinformation that meets the “age and place” requirements of the client'srequest. If the requested last known location information of the targetUE is not stored in the memory 1021, the reusability check means 1023generates an error message and transmits it to the client terminal 101from the report transmit means 1026.

[0062] If the requested last known location information is stored in thememory 1021, the reusability check means 1023 instructs thenotification/verification means 1024 to check the UE's privacy profileto see if notification/verification process must be performed. If thisis the case, the notification/verification means 1024 acquires theidentity of this SGSN/MSC 103 from the home HLR/HSS 106 of the target UE105 and transmits a notification/verification message to SGSN/MSC 103 torequest it to send a notification to the UE 105 for indicating that alocation request is being terminated or a verification message to it torequest it to verify the client terminal. In the former case, theSGSN/MSC 103 proceeds to request the second privacy check means toperform a second privacy check on the last known location information.In the latter case, the target UE returns a verification report to theSGSN/MSC 103, which repeats the report to the second privacy check means1025 to perform a second privacy check if the location request isverified by the target UE.

[0063] The second privacy check involves verifying the location requestagainst the privacy profile of the target UE stored in the memory 1021and determining whether the current or UE's last known locationinformation can be sent to the client terminal. If the location requestis not verified by the second privacy check, an error message is sentfrom the report transmit means 1026 to the client terminal. If thelocation request is verified by the second privacy check, the reporttransmit means 1026 transmits the location information contained in thelocation report from the SGSN/MSC 103 or a copy of the UE's last knownlocation information stored in the memory 1021.

[0064] In a MO-LR mode of operation, the mobile UE terminal 105 includesa control unit 1051 for transmitting a location request via a wirelessinterface 1053 to the RAN 104 for requesting the location information ofits own terminal from the SGSN/MSC 103. The location request is of thesame format as used in transmitting a location request from the clientterminal. SGSN/MSC 103 formulates and transmits a location reportcontaining current or last known location information of the UEterminal, depending on the type of location information specified by thelocation request message. The location report is transferred via the RAN104 to the UE terminal 105 and received and stored in a memory 1052 andthen displayed.

[0065] In FIG. 2B, the privacy profile and location information of thetarget UE are maintained in the SGSN/MSC 103. GMLC 102 includes a clientcheck means 1027 and a report transmit means 1026. Client check means1027 performs a client check on the location request from the clientterminal 101. If the client check means 1027 does not verify the clientterminal 101, it sends an error message to the client terminal from thereport transmit means 1026. Otherwise, the client check means 1027acquires the identity of SGSN/MSC 103 from HLR/HSS 106 and sends aprivacy check request to the SGSN/MSC 103.

[0066] SGSN/MSC 103 includes a first privacy check means 1032, whichreceives the privacy check request and performs a first privacy checkusing the privacy profile of the target UE stored in a memory 1031. Ifthe location request is verified, the first privacy check means 1032determines which of the location information type the verified requestspecifies.

[0067] If the location request specifies type C or C/L, the first clientcheck means 1032 instructs a notification/verification means 1034 totransmit a location request to the RAN 104 to perform a locationestimation process to determine the location of the target UE 105. Alocation report is then returned from the RAN 104 to a second privacycheck means 1035. In response to the location report, the second privacycheck means 1035 proceeds to perform a second privacy check.

[0068] If the location request specifies type L or L/C, the firstprivacy check means 1032 instructs a reusability check means 1033 tomake a search through the memory 1031 for last known locationinformation that meets the “age and place” requirements of the client'srequest. If the requested last known location information of the targetUE is not stored in the memory 1031, the reusability check means 1033generates an error message and transmits it from the report transmitmeans 1036 to the client terminal 101. If the requested last knownlocation information is stored in the memory 1031, the reusability checkmeans 1033 instructs the notification/verification means 1034 to checkthe UE's privacy profile to see if notification/verification processmust be performed. If this is the case, the notification/verificationmeans 1034 transmits a notification to the UE 105 from the RAN 104 forindicating that a location request is being terminated or a verificationmessage to request it to verify the client terminal. In the former case,the notification/verification means 1034 instructs the second privacycheck means 1035 to perform a second privacy check on the last knownlocation information. In the latter case, the second privacy check means1035 receives a verification report from the target UE and proceeds toperform a second privacy check if the client terminal is verified by thetarget UE.

[0069] The second privacy check involves verifying the location requestagainst the privacy profile of the target UE stored in the memory 1031and determining whether the current or UE's last known locationinformation can be sent to the client terminal. If the location requestis verified by the second privacy check, the report transmit means 1036transmits to the GMLC 102 the location information contained in thelocation report from the RAN 104 or a copy of the UE's last knownlocation information stored in the memory 1031.

Second Network Configuration

[0070] According to the second network configuration shown in FIG. 3,the client terminal 111 is the requesting terminal and the target UEterminal 105 is currently establishing its link to the home network A.The privacy profile and location report of the target UE terminal 105are maintained in the home GMLC 102 similar to that shown in FIG. 2A.

[0071] Client terminal 111 includes a transmit means 1111 fortransmitting a location request to the home GMLC 112 and a receive means1112 for receiving a location report from the GMLC 112. GMLC 112includes a request transfer means 1121 which identifies the GMLC 102 asa node that maintains the privacy profile and location information ofthe target UE 105 by acquiring its node identifier from the home HLR/HSS106 of the target UE. GMLC 112 includes a report transfer means 1122 forrepeating a location report from the GMLC 102 to the client terminal111.

[0072] GMLC 102 is of identical configuration to that shown in FIG. 2A.GMLC 102 operates on the location request from the GMLC 112 in a manneridentical to its operation on the location request directly receivedfrom the client terminal 101 of FIG. 2A. Therefore, the description ofGMLC 102 is omitted for simplicity.

Third Network Configuration

[0073] According to the third network configuration shown in FIG. 4,client terminal 111 is the requesting terminal and the target UEterminal 105 is currently visiting the external network C. The privacyprofile and location report of the target UE terminal 105 are maintainedin the home GMLC 102 similar to that shown in FIG. 3.

[0074] Client terminal 111 sends a location request from transmit means1111 to the home GMLC 112 and receives a location report by receivemeans 1112 from the GMLC 112. Similar to FIG. 3, the request transfermeans 1121 repeats the received location request to the GMLC 102 and thereport transfer means 1122 repeats a location report from the GMLC 102to the client terminal 111. In the GMLC 102, memory 1021 maintains theprivacy profile and last known location information of the target UE105. GMLC 102 is of the same configuration as in FIG. 3. The operationof GMLC 102 is the same as that of FIG. 3 except that itsnotification/verification means 1024 sends notification/verification andlocation request messages to the GMLC 122 of the visited network C andits second privacy check means 1025 receives verification and locationreports from the GMLC 122.

[0075] GMLC 122 includes a message transfer means 1221 for repeating themessage from the GMLC 102 to the SGSN/MSC 123 of the visited network Cand a report transfer means 1222 for repeating verification and locationreports from the SGSN/MSC 123 to the GMLC 102.

Fourth Network Configuration

[0076] According to the fourth network configuration shown in FIG. 5,the client terminal 101 is the requesting terminal and the target UEterminal 105 is currently visiting the external network B. The privacyprofile and location report of the target UE 105 are maintained in thehome GMLC 102.

[0077] The location network of this configuration is similar to that ofFIG. 2A with the exception that its notification/verification means 1024sends notification/verification and location request messages to theGMLC 112 of the visited network B and its second privacy check means1025 receives verification and location reports from the GMLC 112.

[0078] GMLC 112 includes a message transfer means 1121 for repeating themessage from the GMLC 102 to the SGSN/MSC 113 of the visited network Band a report transfer means 1122 for repeating verification and locationreports from the SGSN/MSC 113 to the GMLC 102.

[0079] Fifth Network Configuration

[0080] According to the fifth network configuration shown in FIG. 6, theclient terminal 111 is the requesting terminal and the target UEterminal 105 is currently visiting the external network B. The privacyprofile and location report of the target UE terminal 105 are maintainedin the home GMLC 102.

[0081] The location network of this configuration is similar to that ofFIG. 4 with the exception that the GMLC 112 of the visited network Bincludes a transfer means 1123 and the notification/verification means1024 of GMLC 102 sends notification/verification and location requestmessages to the transfer means 1123 for repeating it to the SGSN/MSC 113of the visited network B. The second privacy check means 1025 of GMLC102 receives verification and location reports from the SGSN/MSC 113 viathe transfer means 1123 of GMLC 112.

[0082] Sixth Network Configuration

[0083] The sixth network configuration is shown in FIGS. 7A and 7B inwhich the client terminal 101 is the requesting terminal and the targetUE terminal 105 is currently establishing its link to the home networkA. In FIG. 7A, the privacy profile and location information of thetarget UE terminal 105 are both maintained in the PPR 107.

[0084] In FIG. 7A, the GMLC 102 includes a client check means 1027 toperform a client check on the location request from the client terminal101. If the request is verified, the client check means 1027 transmitsan authorization request to the PPR 107 for authorizing it to perform anumber of checks including a first privacy check, an information typecheck and a reusability test. PPR 107 includes a memory 1061 for storingprivacy profiles and location information of mobile terminals and afirst privacy check means 1072 which receives the authorization requestfrom the GMLC 102 to perform a first privacy check using the privacyprofile stored in the memory 1071. If the request is verified by thefirst privacy check, the location information type of the request isexamined.

[0085] If the client is requesting current location information, thefirst privacy check means 1072 instructs the notification/verificationmeans 1024 to determine if notification/verification is required.Notification/verification means 1024 acquires the identifier of SGSN/MSC103 from the HLR/HSS 106 and sends a location request (and anotification/verification message if required) to the identifiedSGSN/MSC to obtain location information of the target UE (with orwithout a verification report). The obtained location information issupplied to a privacy check request means 1028 of the GMLC 102. Inresponse, the privacy check request means 1028 transmits anauthorization request to a second privacy check means 1075 of the PPR toauthorize it to perform a second privacy check using the UE's privacyprofile stored in the memory 1071. If the request for the currentlocation information is verified by the second privacy check, the secondprivacy check means 1075 permits the privacy check request means 1028 ofGMLC 102 to transmit the current location information which has beenreceived from the SGSN/MSC 103 to the client terminal 101 via the reporttransmit means 1026.

[0086] If the client terminal 101 is requesting last known locationinformation of the target UE, the privacy check means 1072 of the PPRallows the reusability check means 1073 to perform a reusability test onthe “age and place” data of the location request to determine whetherthe requested last known location information is available in the memory1071. If this is the case, the reusability check means 1073 transmitsinformation to the notification/verification means 1024, indicatingwhether or not notification/verification is required. Ifnotification/verification is required, the notification/verificationmeans 1024 transmits a notification/verification message to the SGSN/MSC103. Privacy check request means 1028 responds to a verification reportfrom the SGSN/MSC 103 by checking it to see if second privacy checkshould proceed. If so, it sends an authorization request to a secondprivacy check means 1075 of PPR 107 to authorize it to perform a secondprivacy check by using the privacy profile of the target UE and returnsa privacy check report to the GMLC 102 from report transmit means 1076.If the second privacy check verifies the request, the report transmitmeans 1076 transmits a copy of the last known location information ofthe target UE from the memory 1071 to the GMLC 102, which is repeated bythe report transmit means 1026 to the client terminal 101.

[0087] If any of the results of the two privacy checks and thereusability check is unfavorable, an error report will be transmittedfrom the report transmit means 1076 to the GMLC 102 and repeated by thereport transmit means 1026 to the client terminal 101.

[0088] In FIG. 7B, the privacy profile and location report of the targetUE terminal 105 are respectively maintained by the PPR 107 and the GMLC102. Client check means 1027 performs a client check on the receivedlocation request. If the request is verified, the client check means1027 transmits an authorization request to the PPR 107 to authorize itto perform a first privacy check. PPR 107 includes a privacy check means1077 which references the privacy profile of the UE terminal 105 andperforms a privacy check using the referenced privacy profile. If therequest is not verified, the privacy check means 1077 transmits an errormessage to the GMLC 102 from report transmit means 1076 to the clientterminal 101. If the request is verified, the privacy check means 1077requests the client check means 1027 of the GMLC to examine the type oflocation information of the location request.

[0089] If the client is requesting current location information, theclient check means 1027 of the GMLC instructs thenotification/verification means 1024 to acquire the identifier of theSGSN/MSC 103 from the HLR/HSS 106 and transmits a location request tothe SGSN/MSC 103. Location information obtained by the SGSN/MSC 103 istransmitted to the privacy check request means 1028. Ifnotification/verification by the UE terminal is required, anotification/verification message is sent with the location request anda verification report will be received by the privacy check requestmeans 1028. In response to the location information, the privacy checkrequest means 1028 sends an authorization request to the privacy checkmeans 1077 of the PPR to authorize it to perform a second privacy check.If the request is verified by the second privacy check, the privacycheck means 1077 allows the privacy check request means to transmit thereceived current location information to the client terminal 101 via thereport transmit means 1026.

[0090] If the client terminal 101 is requesting last known locationinformation of the target UE, the client check means 1027 of the GMLCallows the reusability check means 1023 to perform a reusability test onthe “age and place” data of the location request to determine whetherthe requested last known location information is available in the memory1021. If this is the case, the reusability check means 1023 instructsthe notification/verification means 1024 to check to seenotification/verification is required. If notification/verification isrequired, the notification/verification means 1024 transmits anotification/verification message to the SGSN/MSC 103 to receive averification report. Privacy check request means 1028 responds to theverification report by checking it to see if second privacy check shouldproceed. If so, it sends an authorization request to the privacy checkmeans 1077 to authorize it to perform a second privacy check by usingthe privacy profile of the target UE and returns a privacy check reportto the GMLC 102. If the request is verified by the second privacy checkmeans 1077, the report transmit means 1026 is directed to transmit acopy of the last known location information of the target UE from thememory 1021 to the GMLC 102 to the client terminal 101.

Seventh Network Configuration

[0091] The seventh network configuration is shown in FIGS. 8A and 8B inwhich the client terminal 111 is the requesting terminal and the targetUE terminal 105 is currently establishing its link to the home networkA.

[0092] In FIG. 8A, the privacy profile and location information of thetarget UE terminal 105 are both maintained in the PPR 107. Clientterminal 111 includes a transmit means 1111 for transmitting a locationrequest to the home GMLC 112 and a receive means 1112 for receiving alocation report from the GMLC 112. GMLC 112 includes a request transfermeans 1121 which identifies the GMLC 102 as a node that maintains theprivacy profile and location information of the target UE 105 byacquiring its node identifier from the home HLR/HSS 106 of the targetUE. GMLC 112 includes a report transfer means 1122 for repeating alocation report from the GMLC 102 to the client terminal 111.

[0093] GMLC 102 and PPR 107 are of identical configuration to that shownin FIG. 7A and hence they operate in the same manner as that of FIG. 7Aon the location request repeated by the GMLC 112.

[0094] In FIG. 8B, the privacy profile and location information of thetarget UE terminal 105 are respectively maintained in the GMLC 102 andPPR 107.

[0095] Similar to FIG. 8A, the client terminal 111 transmits a locationrequest to the home GMLC 112 and receives a location report from theGMLC 112. GMLC 102 and PPR 107 are of identical configuration to thatshown in FIG. 7B and hence they operate in the same manner as that ofFIG. 7B on the location request repeated by the GMLC 112.

Eighth Network Configuration

[0096] The eighth network configuration is shown in FIGS. 9A and 9B inwhich the client terminal 111 is the requesting terminal and the targetUE terminal 105 is currently visiting the external network C.

[0097] In FIG. 9A, the privacy profile and location information of thetarget UE terminal 105 are both maintained in the PPR 107. Clientterminal 111 transmits a location request to the home GMLC 112 andreceives a location report from the GMLC 112. GMLC 112 includes requesttransfer means 1121 which identifies the GMLC 102 as a node thatmaintains the privacy profile and location information of the target UE105 by acquiring its node identifier from the home HLR/HSS 106 of thetarget UE. GMLC 112 includes report transfer means 1122 for repeating alocation report from the GMLC 102 to the client terminal 111.

[0098] Since the target UE is visiting the network C, thenotification/verification means 1024 acquires the identifiers of GMLC122 and SGSN/MSC 123 from the HLR/HSS 106 when instructed from the PPR107 and sends a location request and notification/verification messageto the SGSN/MSC 123 via the message transfer means 1221 of GMLC 122 andreceives a location report and verification report via the reporttransfer means 1222 of GMLC 122.

[0099] In FIG. 9B, the privacy profile and location information of thetarget UE terminal 105 are respectively maintained in the GMLC 102 andPPR 107.

[0100] The operation of FIG. 9B is similar to FIG. 8B with the exceptionthat location report and verification report are obtained from theSGSN/MSC 123 via the GMLC 122.

Ninth Network Configuration

[0101] The ninth network configuration is shown in FIGS. 10A and 10B inwhich the client terminal 101 is the requesting terminal and the targetUE terminal 105 is currently visiting the external network B.

[0102] In FIG. 10A, the privacy profile and location information of thetarget UE terminal 105 are both maintained in the PPR 107. Clientterminal 101 transmits a location request to the home GMLC 102 andreceives a location report from the GMLC 102. Since the target UE isvisiting the network B, the notification/verification means 1024 of GMLC102 acquires the identifiers of GMLC 112 and SGSN/MSC 113 from theHLR/HSS 106 when instructed from the PPR 107 and sends a locationrequest and notification/verification message to the SGSN/MSC 113 viathe message transfer means 1123 of GMLC 112 and receives a locationreport and verification report via the report transfer means 1124 ofGMLC 112.

[0103] In FIG. 10B, the privacy profile and location information of thetarget UE terminal 105 are respectively maintained in the GMLC 102 andPPR 107.

[0104] The operation of FIG. 10B is similar to FIG. 8B with theexception that location report and verification report are obtained fromthe SGSN/MSC 113 via the GMLC 112.

Tenth Network Configuration

[0105] The ninth network configuration is shown in FIGS. 11A and 11B inwhich the client terminal 111 is the requesting terminal and the targetUE terminal 105 is currently visiting the external network B.

[0106] In FIG. 11A, the privacy profile and location information of thetarget UE terminal 105 are both maintained in the PPR 107. Clientterminal 111 transmits a location request to the home GMLC 112 whichrepeats the request to the GMLC 102 after acquiring its identifier fromthe HLR/HSS 106. Client terminal 111 receives a location report from theGMLC 102 via the home GMLC 112. Since the target UE is visiting thenetwork B, the notification/verification means 1024 of GMLC 102 acquiresthe identifiers of GMLC 112 and SGSN/MSC 113 from the HLR/HSS 106 wheninstructed from the PPR 107 and sends a location request andnotification/verification message to the SGSN/MSC 113 via the messagetransfer means 1123 of GMLC 112 and receives a location report andverification report via the report transfer means 1124 of GMLC 112.

[0107] In FIG. 11B, the privacy profile and location information of thetarget UE terminal 105 are respectively maintained in the GMLC 102 andPPR 107.

[0108] The operation of FIG. 11B is similar to FIG. 8B with theexception that location report and verification report are obtained fromthe SGSN/MSC 113 via the GMLC 112.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0109] The MT-LR operation of a local GMLC proceeds according toflowcharts shown in FIGS. 12A to 12E if the GMLC holds the privacyinformation of its home UE terminals.

[0110] In FIG. 12A, when the local GMLC receives a message from a clientterminal or from the network, the routine starts with decision step 201to examine the type and source of the message to determine whether themessage is a location request from a client terminal, a location requestrepeated from other GMLC, or the message contains an SGSN/MSC identifierfrom an HLR/HSS. If the message is a location request from clientterminal, flow proceeds to step 202 to perform a client check to verifythe requesting client terminal for agreement with the privacy profile ofthe target UE maintained in the local GMLC. If the location request isnot verified at step 202, an error message is transmitted to therequesting terminal (step 223) and the routine is terminated.

[0111] If the requesting client is verified (step 202) or the receivedmessage is a location request from other GMLC (step 201), flow proceedsto step 204 to determine whether the local GMLC is the home GMLC of thetarget UE. If this is the case, flow proceeds to decision step 205 tocheck to see if a PPR (Privacy Profile Register) is connected to theGMLC.

[0112] If no PPR is connected to the local GMLC, a first privacy checkis performed on the location request for agreement with the privacyprofile of the target UE terminal (step 206) to determine if thelocation request is acceptable (step 207).

[0113] The first privacy profile of a UE terminal may includegrant/reject indication of whether or not the client terminal isacceptable, or whether or not the requested accuracy of locationinformation is acceptable, or whether or not the requested age of lastknown location information is acceptable. The first privacy profile mayfurther include an indication of whether the UE terminal user isdesirous of notification from the client terminal or verification by theUE terminal as a criteria for the acceptance of a location request. If aUE user desires notification from the requester, the UE user willreceive a notification from the network indicating that the UE terminalis being the target of a location request. If a UE user desiresverification, the user will receive a verification message from thenetwork indicating whether the current location request should beaccepted or not. The UE terminal responds to the verification messagewith a verification report.

[0114] If first privacy check step 207 determines that the receivedlocation request is not acceptable, flow proceeds to step 223 totransmit an error message to the requesting terminal. If the locationrequest is acceptable, flow proceeds to step 208 to perform a check onthe type of location information contained in the received locationrequest to determine which of the parameters (C, L, C/L and L/C) isspecified in the request (step 209). If the type of location informationspecifies last known (L) or “last known or current (L/C) locationinformation” (indicating that the client user desires last knownlocation information but satisfies with it if current locationinformation is not available), flow proceeds to step 210 to perform acheck on the last known location information for reusability. If therequested “age and place” requirements of the location request meet theprivacy profile of the target UE, a further check is made as to whetherlast known location information that fulfills the requirements is storedin memory (step 211).

[0115] If such last known location information is available, flowproceeds to step 212 to check to see if the privacy profile of thetarget UE indicates that notification to or verification by the targetUE is required. If this is the case, flow proceeds to step 213 to sendan enquiry message to an HLR/HSS for requesting the identifier of aSGSN/MSC responsible for the target UE terminal. If no response isreceived from the HLR/HSS, an error message is sent to the clientterminal (step 223). When a response message is received from theHLR/HSS (step 214), the GMLC proceeds to step 215 to examine itscontents and transmits a notification/verification message to theidentified SGSN/MSC if the response message contains only SGSN/MSCidentifier. If the response message from the HLR/HSS contains theidentifier of a GMLC in addition to an SGSN/MSC identifier, the GMLCsends the notification/verification message to the identified GMLC. Ifthe privacy profile of the target UE requires only notification (step216), flow proceeds to step 218. Otherwise, flow proceeds to step 217 tocheck to see if a verification report from the UE terminal indicatesthat the requesting client terminal is verified. If the decision isnegative at step 217, flow proceeds to step 223 to send an error messageto the requesting terminal. If the decision at step 217 is affirmative,flow proceeds to step 218 to determine if the GMLC is connected to aPPR.

[0116] If no PPR is connected to the GMLC (step 218), flow proceeds tostep 219 to perform a second privacy check on the current or last knownlocation information to determine whether its time of locationestimation and its estimated location agree with allowed “time-zone andarea” parameters of the UE's privacy profile (step 220). If the resultof the second privacy check is unfavorable (step 220), an error messageis transmitted to the client terminal (step 223). Otherwise, thelocation information is processed according to the UE's privacy profileif the accuracy of the location information is higher than the allowedaccuracy (step 221). At step 222, the location information (current orlast known) is transmitted to the client terminal. If the locationinformation is current and a copy of the current location information isstored in memory as last known location information.

[0117] If no notification/verification is required by the UE terminal,the decision at step 212 is negative and flow proceeds to step 219 toperform second privacy check, skipping steps 214 through 218.

[0118] If current (C or C/L) location information is specified in thereceived location request (step 209) or last known location informationis not available (step 211), flow proceeds to step 231 (FIG. 12B) totransmit an enquiry message to the home HLR/HSS for requesting theidentifier of a SGSN/MSC responsible for the target UE terminal. Whenthe requested identifier is received (step 232), flow proceeds to step233 to check to see if the privacy profile of the target UE indicatesthat notification/verification is required. If not, a location requestis sent to the home or external SGSN/MSC depending on the currentlocation of the target UE to obtain its current location information.When the requested current location information is received (step 235),flow returns to step 218. If there is no response, an error message istransmitted to the requesting terminal (step 223). If the decision atstep 233 is affirmative, flow proceeds to step 236 to transmit alocation request and notification/verification request message to thehome or external SGSN/MSC depending on the current location of thetarget UE for receiving a response (step 237). If the current locationinformation of the target UE and a verification report is received, flowproceeds from step 237 to step 217. If no response is received, flowproceeds from step 237 to step 223 to send an error message to theclient terminal.

[0119] If the decision at step 204 indicates that the local GMLC is notthe home GMLC of the target UE, flow proceeds to step 241 (FIG. 12C) tosend an enquiry message to the external HLR/HSS, which is the homeHLR/HSS of the external target UE, to obtain the identifier of anappropriate GMLC. When the identifier of the appropriate GMLC isobtained, a location request is transmitted to the identified GMLC toobtain the location information of the target UE. If the locationinformation is received successfully, flow proceeds to step 222 torepeat the received location information to the requesting terminal. Ifno response is returned, an error message is sent to the requestingterminal (step 223).

[0120] If the decision at step 201 indicates that a message such asnotification/verification message, verification report, locationrequest, or location report is received from other GMLC, flow proceedsfrom step 201 to step 251 (FIG. 12D) to repeat the received message todownstream node identified by a SGSN/MSC (or plus GMLC) identifiercontained in the message.

[0121] If a PPR is connected to the local GMLC, the decision at step 205is affirmative and flow proceeds to step 224 to send an authorizationrequest (for privacy check with or without a location-info-type check)to the PPR to obtain a report. The PPR performs a first privacy check onthe location request and additionally an information-type check with anattendant reusability test on stored location information of the targetUE if the PPR maintains location information of mobile terminals. Atstep 225, the GMLC receives a report from the PPR indicating a result ofthe first privacy check and a result of the reusability test. Step 225analyzes the received report. If the result of the first privacy checkis favorable and no reusability test is performed (a), flow proceeds tostep 208. Otherwise, flow proceeds to step 223 to send an error messageto the requesting terminal. If the results of the first privacy checkand reusability test are both favorable (b), flow proceeds to decisionstep 212. If the result of the first privacy check is favorable, but theresult of the reusability test is unfavorable (c), flow proceeds to step231 (FIG. 12B).

[0122] If the decision at step 218 is affirmative, flow proceeds to step261 (FIG. 12E) to send a request to the PPR for requesting it to performa second privacy check. At step 262, a report indicating a result of thesecond privacy check is received from the requested PPR and the resultis analyzed. If the result indicates a favorable decision, flow proceedsfrom step 262 to step 222 to transmit the location information of thetarget UE to the requesting terminal. If the report from the PPRindicates an error at step 262, flow proceeds to step 223 to send anerror message to the requesting terminal or GMLC.

[0123] If the privacy information of home UE terminals is not maintainedin the local GMLC, the MT-LR operation of the GMLC proceeds according tothe flowchart of FIG. 12F and the home SGSN/MSC of target UE terminaloperates according to the flowchart of FIG. 13.

[0124] In FIG. 12F, the routine starts with step 271 to check the typeand source of a message when it arrives on the local GMLC. If themessage is a location request from a client terminal, flow proceeds tostep 272 to perform a client check. If the client terminal is verified(step 273), flow proceeds to step 274 to check to see if the local GMLCis the home GMLC of the target UE. If so, flow proceeds to step 231(FIG. 12B). Otherwise, flow proceeds to step 241 (FIG. 12C). If themessage is a location request from other GMLC, steps 272, 273 areskipped and step 274 is executed. If the message contains a nodeidentifier, flow proceeds from step 271 to step 251 to repeat themessage downstream.

[0125] The MT-LR operation of the SGSN/MSC of the present invention willbe described below with reference to the flowchart of FIG. 13.

[0126] The routine of a SGSN/MSC begins with the reception of a messageeither from a GMLC or a mobile UE terminal (step 300). If the locationrequest is transmitted from a GMLC and the SGSN/MSC maintains locationreports and private profiles of UE terminals (step 301), flow proceedsto step 302 to perform a privacy check for agreement with the firstprivacy profile of the target UE. If the request is acceptable, flowproceeds to step 304 to check the location information type of therequest. If the request is not acceptable (step 303), an error messageis returned to the requesting GMLC (step 315).

[0127] If the location reports and private profiles of UE terminals arenot maintained by the SGSN/MSC, flow proceeds to step 331 to transmit alocation request to the RAN and repeats a location report from the RANto the requesting GMLC (step 332).

[0128] If the decision at step 300 indicates that the location requestis transmitted from a UE terminal, flow proceeds to step 304, skippingsteps 302 and 303.

[0129] If the location request specifies last known location informationof the target UE (step 304), a reusability test is provided (steps 306,307). If the result of the reusability test at step 307 is unfavorable,flow proceeds to step 308 to transmit a location request to theassociated RAN to obtain the current location information of the targetUE (steps 308, 309). If no response is received, an error message istransmitted to the requesting source (step 315).

[0130] If the decision at step 307 or 309 is affirmative, flow proceedsto step 310. If the location request has been received from a GMLC, flowproceeds to step 311 to perform a privacy check for agreement with asecond privacy profile of the target UE terminal (step 312). If theresult of the privacy check is unfavorable, an error message is returnedto the requesting source (step 315). Otherwise, flow advances to step313 to process the location information according to the privacy profileif the accuracy of the location information (either current or lastknown) is higher than the allowed accuracy. The processed locationinformation is then transmitted to the requesting source (step 314). Ifthe location request has been received from a UE terminal, flow proceedsfrom step 310 to step 314 to transmit the location information to therequesting UE terminal.

[0131] If the SGSN/MSC receives a notification/verification message froma GMLC (step 300), flow proceeds to step 320 to check to see ifnotification or verification is requested. If notification is requested,flow proceeds to step 321 to send a notification message to the targetUE and terminates the routine. If verification by the target UE isrequested, flow proceeds to step 322 to send a verification message tothe target UE. In response, the target UE checks the requesting terminaland sends a verification report to the SGSN/MSC. This report is repeatedby the SGSN/MSC to the requesting GMLC (step 323).

[0132] The MO-LR operation of the mobile UE terminal of the presentinvention proceeds according to a flowchart shown in FIG. 14.

[0133] The routine of a mobile UE terminal starts with step 401 when theuser of the UE enters a request to the terminal for requesting alocation information of its own terminal. The entered request dataspecifies one of the types of location information as described above.At step 402, the UE terminal checks the entered type of locationinformation and determines which type is specified (step 403). If thelast known location information is requested, flow proceeds to step 404to determine whether past location information is stored in the memory1052 (FIG. 2A) of the UE terminal. If the decision is affirmative atstep 404, flow proceeds to step 405 to check the stored last knownlocation information for reusability (step 406). If the storedinformation satisfies the privacy profile of the UE terminal, the storedlocation information is determined to be reusable and the storedinformation is read (step 407) and displayed on a map (step 411). If thedecision at step 403 indicates that the entered request specifiescurrent location of the UE terminal or if the decision at step 404 or406 is negative, flow proceeds to step 408 to transmit a locationrequest to a SGSN/MSC via a RAN. The location request is processed inthe SGSN/MSC and location information is transmitted from the SGSN/MSCand received by the UE terminal at step 409. Depending on the type oflocation information specified in the transmitted location requestmessage, the location information received from the SGSN/MSC is eitherlast known or current location information of the requesting UEterminal. The memory of the UE terminal is updated with the receivedlocation information at step 410 and the received information isdisplayed (step 411).

NETWORK MODES OF OPERATION

[0134] The present invention operates in first to tenth network modescorresponding respectively to the first to tenth network configurationsdiscussed previously. The following is a description of the networkmodes of operation using the flowcharts just described above.

First Network Mode

[0135]FIG. 15A is a sequence diagram illustrating a location networkoperating in MT-LR mode in which the client terminal 101 is therequesting terminal and the mobile terminal 105 is the target UE whichis currently staying in the home network A. The home GMLC 102 of targetUE maintains its privacy profile and location report. Client terminal101 initially transmits a location request (event 501) to the home GMLC102. In response, the GMLC 102 performs a client check (event 502), aprivacy check (event 503) and a location information type check (event504) by executing steps 200 through 211 of FIG. 12A. If the locationrequest specifies current location information of the target UE andnotification/verification is not required, steps 231 through 235 areexecuted by sending a location request to the SGSN/MSC 103 using itsidentifier acquired from HLR/HSS 106 (events 505, 506, 507).

[0136] If the location request specifies last known location informationof the target UE and the stored information is reusable (step 211), andnotification/verification is required (step 212), steps 213 through 215are executed by sending a notification/verification request to theSGSN/MSC 103 using its identifier obtained from HLR/HSS 106 (events 505,506, 507).

[0137] SGSN/MSC 103 executes steps 300, 320-323 in response to thenotification/verification message (event 507) from the GMLC 102 orexecutes steps 300, 301, 331, 332 in response to the location requestfrom the GMLC 102 (event 508) and transmits a location report or averification report (event 509) to the GMLC 102. If verification reportis received, the GMLC 102 checks to see if the target UE has verifiedthe request (step 217). If the request is verified, the GMLC 102performs a second privacy check (event 510) on the current or last knownlocation information by executing steps 219 to 221 and transmitslocation information to the client terminal 101 (event 511).

[0138]FIG. 15B is a sequence diagram illustrating a location networkoperating in the MT-LR mode in which the client terminal 101 is therequesting terminal, the mobile terminal 105 is the target UEestablishing its wireless link to the home network A, and the homeSGSN/MSC 103 of target UE maintains its privacy profile and locationreport. Client terminal 101 transmits a location request (event 601) tothe home GMLC 102. In response, the GMLC 102 executes steps 271˜273(FIG. 12F) to perform a client check (event 602). Being the home GMLC ofthe target UE, the GMLC 102 makes an affirmative decision at step 274and executes steps 231, 232 (FIG. 12B) to acquire the identifier ofSGSN/MSC 103 (events 603, 604) from HLR/HSS 106 and sends a locationrequest to the SGSN/MSC 103 (event 605).

[0139] In response to the location request from GMLC 102, the SGSN/MSC103 executes steps 300˜307 to perform a first privacy check andinformation type check (events 606, 607) and executes steps 308, 309 toperform location estimation process (event 608) to obtain a locationreport. Second privacy check is performed (event 609) by the SGSN/MSC103 by executing steps 310˜313. The location report is then transmitted(step 314) to the GMLC 102 (event 610), which receives this locationreport (step 235, FIG. 12B) and repeats it to the client terminal 101(step 222, FIG. 12A, event 611).

[0140] In FIG. 15C, the location network operates in MO-LR mode in whichthe UE terminal 105 transmits a location request to the SGSN/MSC 103(event 701). SGSN/MSC 103 responds to this request by executing steps300, 304 and 305 (FIG. 13) to perform an information type check (event702). If the current location is specified in the location request, theSGSN/MSC 103 sends a location request to the RAN 104 (steps 308, 309,310, 314) to provide a location estimation process (event 703). If lastknown location is specified in the location request, the SGSN/MSC 103performs a reusability test (steps 306, 307) and sends a location report(event 704) to the UE terminal (steps 310, 314).

Second Network Mode

[0141]FIG. 16 is a sequence diagram illustrating a location networkoperating in the MT-LR mode in which the client terminal 111 is therequesting terminal, the mobile terminal 105 is the target UE which iscurrently staying in its home network A, and the home GMLC 102 of targetUE 105 maintains its privacy profile and location report. Clientterminal 111 initially transmits a location request (event 801) to thehome GMLC 112. In response, the GMLC 112 executes steps 201˜203 (FIG.12A) to perform a client check (event 802). Since the privacyinformation of the target UE is not available, the GMLC 112 passesthrough steps 204, 205 and executes steps 241 and 242 (FIG. 12C) toacquire the identifier of GMLC 102 (events 803, 804) from the homeHLR/HSS 106 of the target UE 105 and sends a location request to theGMLC 102 (event 805).

[0142] In response to the location request from GMLC 112, the GMLC 102passes through steps 201, 204 and executes steps 206˜211 to perform afirst privacy check and information type check (events 806, 807) andexecutes steps 212˜215 to obtain the identifier of SGSN/MSC 103 fromHLR/HSS 106 (events 808, 809) and transmit a notification/verificationmessage or a location request (event 810) to the SGSN/MSC 103. SGSN/MSC103 performs its routine (event 811) and returns a location report or averification report to the GMLC 102 (event 812). In response, the GMLC102 executes steps 216˜218 and then performs a second privacy check onthe received location information (steps 219, 220, 221, event 813). Thelocation report is then transmitted (step 222, event 814) to therequesting GMLC 112, which receives this location report (step 242, FIG.12C) and repeats it to the client terminal 111 (step 222, FIG. 12A,event 815).

Third Network Mode

[0143]FIG. 17 is a sequence diagram illustrating a location networkoperating in the MT-LR mode in which the client terminal 111 is therequesting terminal, the mobile terminal 105 is the target UE which iscurrently visiting the external network C, and the home GMLC 102 oftarget UE 105 maintains its privacy profile and location report. Clientterminal 111 initially transmits a location request 901 to the home GMLC112. In response, the GMLC 112 executes steps 201˜203 (FIG. 12A) toperform a client check 902. Since the privacy information of the targetUE is not available, the GMLC 112 passes through steps 204, 205 andexecutes steps 241 and 242 (FIG. 12C) to acquire the identifier of GMLC102 (events 903, 904) from the home HLR/HSS 106 of the target UE 105 andsends a location request 905 to the GMLC 102.

[0144] In response to the location request from GMLC 112, the GMLC 102passes through steps 201, 204 and executes steps 206˜211 to perform afirst privacy check 906 and information type check 907 and executessteps 212˜215 to obtain the identifiers of SGSN/MSC 123 and GMLC 122from HLR/HSS 106 (events 908, 909). On receiving these identifiers, theGMLC 102 executes step 215 and transmits a notification/verificationrequest or a location request 910 to the GMLC 122. Each of theserequests contains the identifiers of SGSN/MSC 123 and GMLC 122. Inresponse to the request message from the GMLC 102, the GMLC 122 passesthrough step 201 to step 251 (FIG. 12D) to repeat the received requestmessage to the SGSN/MSC 123. SGSN/MSC 123 performs its routine 911 andreturns a location report or a verification report 912 to the GMLC 112,which repeats it to the GMLC 102 (step 252, FIG. 12D).

[0145] GMLC 102 executes steps 216˜218 for verification and thenperforms a second privacy check 913 on the received location information(steps 219, 220, 221). The location report 914 is then transmitted (step222) to the requesting GMLC 112, which repeats this location report 915(steps 242, 222) to the client terminal 111.

Fourth Network Mode

[0146]FIG. 18 is a sequence diagram illustrating a location networkoperating in the MT-LR mode in which the client terminal 101 is therequesting terminal, the mobile terminal 105 is the target UE which iscurrently visiting the external network B, and the home GMLC 102 oftarget UE 105 maintains its privacy profile and location report. Clientterminal 101 initially transmits a location request 1001 to the homeGMLC 102. In response, the GMLC 102 executes steps 200 through 211 (FIG.12A) to perform a client check (event 1002), a privacy check 1003 and aninformation type check 1004. Since the target UE is visiting the networkof SGSN/MSC 113, the GMLC 102 acquires the identifiers of SGSN/MSC 113and GMLC 112 (events 1005, 1006) from HLR/HSS 106 when its has executedsteps 212 and 213, and sends a notification/verification or locationrequest message (each containing the acquired node identifiers) to theGMLC 112 (event 1007). GMLC 112 executes steps 201, 251 (FIG. 12D) torepeat the received request message to the SGSN/MSC 113.

[0147] SGSN/MSC 113 executes steps 300, 320˜323 of FIG. 13 in responseto the notification/verification message from the GMLC 112 or executessteps 300, 321˜332 in response to the location request 1008 from theGMLC 112 and sends a location report or a verification report 1009 tothe GMLC 112. GMLC 112 executes step 252 (FIG. 12D) to repeat thereceived report message to the GMLC 102.

[0148] If verification report is received, the GMLC 102 checks to see ifthe target UE has verified the request (step 217). If the request isverified, the GMLC 102 performs a second privacy check 1010 on thecurrent or last known location information by executing steps 219 to 221and transmits location information 1011 to the client terminal 101.

Fifth Network Mode

[0149]FIG. 19 is a sequence diagram illustrating a location networkoperating in the MT-LR mode in which the client terminal 111 is therequesting terminal, the mobile terminal 105 is the target UE which iscurrently visiting the external network B, and the home GMLC 102 oftarget UE 105 maintains its privacy profile and location report. Clientterminal 111 initially transmits a location request 1101 to the homeGMLC 112. In response, the GMLC 112 executes steps 201˜203 (FIG. 12A) toperform a client check 1102. Since the privacy information of the targetUE is not available, the GMLC 112 passes through steps 204, 205 andexecutes steps 241 and 242 (FIG. 12C) to acquire the identifier of GMLC102 (events 1103, 1104) from the home HLR/HSS 106 of the target UE 105and sends a location request 1105 to the GMLC 102.

[0150] In response to the location request from GMLC 112, the GMLC 102passes through steps 201, 204 and executes steps 206˜211 to perform afirst privacy check 1106 and information type check 1107 and executessteps 212˜215 to obtain the identifiers of SGSN/MSC 113 and GMLC 112from HLR/HSS 106 (events 1108, 1109). On receiving these identifiers,the GMLC 102 executes step 215 and transmits a notification/verificationrequest or a location request 1110 to the GMLC 112. Each of theserequests contains the identifiers of SGSN/MSC 113 and GMLC 112. Inresponse to the request message from the GMLC 102, the GMLC 112 passesthrough step 201 to step 251 (FIG. 12D) to repeat the received requestmessage to the SGSN/MSC 113. SGSN/MSC 113 performsnotification/verification or location estimation routine 1111 andreturns a location report or a verification report 1112 to the GMLC 112,which repeats the report to the GMLC 102 (step 252, FIG. 12D).

[0151] GMLC 102 executes steps 216˜218 for verification and thenperforms a second privacy check 1113 on the received locationinformation (steps 219, 220, 221). If the privacy check result isfavorable, the location report 1114 is transmitted from the GMLC 102(step 222) to the requesting GMLC 112, which repeats this locationreport 1115 to the client terminal 111 (steps 242, 222).

Sixth Network Mode

[0152]FIG. 20 is a sequence diagram illustrating a location networkoperating in the MT-LR mode in which the client terminal 101 is therequesting terminal and the mobile terminal 105 is the target UE whichis staying in the home network A. The PPR 107 is connected to the GMLC102. The privacy profile and location report of target UE 105 aremaintained in the PPR 107. Client terminal 101 initially transmits alocation request 1201 to the home GMLC 102. In response, the GMLC 102performs a client check 1202 (steps 202˜203) and sends an authorizationrequest 1203 to the PPR 107 (steps 204, 224). PPR 107 performs a firstprivacy check 1204 and a location information type check 1205 andreturns a report message 1206. Alternatively, information type check1207 may be provided by the GMLC 102.

[0153] GMLC 102 analyzes the received report message 1206 (step 225) andexecutes steps 212 and 213 to send an enquiry message 1208 to HLR/HSS106 to acquire the identifier 1209 of SGSN/MSC 103 and transmits anotification/verification message or a location request message 1210 tothe SGSN/MSC 103.

[0154] SGSN/MSC 103 performs a notification/verification process orlocation estimation process 1211 and returns a location report orverification report message 1212 to the GMLC 102.

[0155] In response to the report message, the GMLC 102 sends anauthorization request 1213 to the PPR 107 (steps 216, 217, 218, 261) toauthorize it to perform a second privacy check 1214 and then analyzes aprivacy check report 1215 from the PPR 107, indicating a result of thesecond privacy check (step 262). If the result of the privacy check isfavorable, the GMLC 102 repeats the location information 1216 receivedfrom the SGSN/MSC 103 to the client terminal 101.

Seventh Network Mode

[0156]FIG. 21 is a sequence diagram illustrating a location networkoperating in MT-LR mode in which the client terminal 111 is therequesting terminal and the mobile terminal 105 is the target UE whichis located in the home network A. The privacy profile and locationreport of target UE 105 are maintained in the PPR 107 connected to theGMLC 102. Client terminal 111 initially transmits a location request1301 to the home GMLC 112. In response, the GMLC 112 performs a clientcheck 1302 (steps 202˜203) and transmits an enquiry message 1303 to theHLR/HSS 106 to acquire the identifier 1304 of the home GMLC 102 of thetarget UE. Using the acquired identifier, the GMLC 112 sends a locationrequest 1305 to the GMLC 102. GMLC 102 responds to the location requestby transmitting an authorization request 1306 to the PPR 107. PPR 107performs a first privacy check 1307 and an information type check 1308and returns a report message 1309 to the GMLC 102.

[0157] GMLC 102 analyzes the received report (step 225) and executessteps 212 and 213 to acquire the identifier of SGSN/MSC 103 from HLR/HSS106 (events 1310, 1311) and transmits a notification/verificationmessage or a location request message 1312 to the SGSN/MSC 103.

[0158] SGSN/MSC 103 performs a notification/verification process orlocation estimation process 1313 and returns a location report orverification report message 1314 to the GMLC 102.

[0159] In response to the report message 1314, the GMLC 102 sends anauthorization request 1315 to the PPR 107 (steps 216, 217, 218, 261) toauthorize it to perform a second privacy check 1316 and analyzes aprivacy check report 1317 from the PPR 107 (step 262). If the result ofthe privacy check is favorable, the GMLC 102 sends the locationinformation 1319 received from the SGSN/MSC 103 to the client terminal101.

Eighth Network Mode

[0160]FIG. 22 is a sequence diagram illustrating a location networkoperating in the MT-LR mode in which the client terminal 111 is therequesting terminal and the mobile terminal 105 is the target UE whichis visiting the external network C. The privacy profile and locationreport of target UE 105 are maintained in the PPR 107 connected to theGMLC 102. Client terminal 111 transmits a location request 1401 to thehome GMLC 112. In response, the GMLC 112 performs a client check 1402and transmits an enquiry message 1403 to the HLR/HSS 106 to acquire theidentifier 1404 of the home GMLC 102 of the target UE. Using theacquired identifier, the GMLC 112 sends a location request 1405 to theGMLC 102. GMLC 102 responds to the location request by transmitting anauthorization request 1406 to the PPR 107. PPR 107 performs a firstprivacy check 1407 and an information type check 1408 and returns areport message 1409 to the GMLC 102.

[0161] GMLC 102 acquires the identifiers of SGSN/MSC 123 and GMLC 122from HLR/HSS 106 (events 1410, 1411) and transmits anotification/verification message or a location request message 1412 tothe SGSN/MSC 123 via the GMLC 122.

[0162] SGSN/MSC 123 performs a notification/verification process orlocation estimation process 1413 and returns a location report orverification report message 1414 to the GMLC 102 via the GMLC 122. Inresponse to the report message 1414, the GMLC 102 sends an authorizationrequest 1415 to the PPR 107 to authorize it to perform a second privacycheck 1416 and analyzes a privacy check report 1417 from the PPR 107. Ifthe result of the privacy check is favorable, the GMLC 102 sends thelocation information 1418 received from the SGSN/MSC 123 to the GMLC112, which sends location information 1419 to the client terminal 111.

Ninth Network Mode

[0163]FIG. 23 is a sequence diagram illustrating a location networkoperating in the MT-LR mode in which the client terminal 101 is therequesting terminal and the target UE 105 is visiting the externalnetwork B. The privacy profile and location report of the target UE aremaintained in the PPR 107 connected to the GMLC 102. Client terminal 101transmits a location request 1501 to the home GMLC 102. In response, theGMLC 102 performs a client check 1502 and transmits an authorizationrequest 1503 to the PPR 107. PPR 107 performs a first privacy check 1504and an information type check 1505 and returns a report message 1506 tothe GMLC 102.

[0164] GMLC 102 acquires the identifiers of SGSN/MSC 113 and GMLC 112from HLR/HSS 106 (events 1507, 1508) and transmits anotification/verification message or a location request message 1509 tothe SGSN/MSC 113 via the GMLC 112.

[0165] SGSN/MSC 113 performs a notification/verification process orlocation estimation process 1510 and returns a location report orverification report message 1511 to the GMLC 102 via the GMLC 112. Inresponse to the report message 1511, the GMLC 102 sends an authorizationrequest 1512 to the PPR 107 to authorize it to perform a second privacycheck 1513 and analyzes a privacy check report 1514 from the PPR 107. Ifthe result of the privacy check is favorable, the GMLC 102 sendslocation information 1515 received from the SGSN/MSC 113 to the clientterminal 101.

Tenth Network Mode

[0166]FIG. 24 is a sequence diagram illustrating a location networkoperating in MT-LR mode in which the client terminal 111 is therequesting terminal and the target UE 105 is visiting the externalnetwork B. The privacy profile and location report of target UE 105 aremaintained in the PPR 107 connected to the GMLC 102. Client terminal 111transmits a location request 1601 to the home GMLC 112. In response, theGMLC 112 performs a client check 1602 and transmits an enquiry message1603 to the HLR/HSS 106 to acquire the identifier 1604 of the home GMLC102 of the target UE. Using the acquired identifier, the GMLC 112 sendsa location request 1605 to the GMLC 102. GMLC 102 responds to thelocation request by transmitting an authorization request 1606 to thePPR 107. PPR 107 performs a first privacy check 1607 and an informationtype check 1608 and returns a report message 1609 to the GMLC 102.

[0167] GMLC 102 acquires the identifiers of SGSN/MSC 113 and GMLC 112from HLR/HSS 106 (events 1610, 1611) and transmits anotification/verification message or a location request message 1612 tothe SGSN/MSC 113 via the GMLC 112.

[0168] SGSN/MSC 113 performs a notification/verification process orlocation estimation process 1613 and returns a location report orverification report message 1614 to the GMLC 102 via the GMLC 112.

[0169] In response to the report message 1614, the GMLC 102 sends anauthorization request 1615 to the PPR 107 to authorize it to perform asecond privacy check 1616 and analyzes a privacy check report 1617 fromthe PPR 107. If the result of the privacy check is favorable, the GMLC102 sends the location report 1618 received from the SGSN/MSC 113 to theGMLC 112 which transmits the location information 1619 to the clientterminal 111.

What is claimed is:
 1. A location system for locating a plurality ofmobile terminals, comprising: a communication terminal for transmittinga location request specifying a target mobile terminal and a type oflocation information; and a location network responsive to said locationrequest from said communication terminal for producing current locationinformation of the target mobile terminal if the type of locationinformation of the received request specifies current locationinformation and transmitting the current location information to saidcommunication terminal and storing the last known location informationin a memory as last known location information of the target mobileterminal, and copying stored last known location information of thetarget mobile terminal from the memory if said type of locationinformation specifies last known location information and transmittingthe copied information to said communication terminal.
 2. The locationsystem of claim 1, wherein said location network performs a reusabilitytest on the stored last known location information and transmits saidlast known location information if the reusability test indicates afavorable result and transmits said current location information if thereusability test indicates an unfavorable result.
 3. The location systemof claim 2, wherein said location request contains a parameter of lastknown location information, and wherein said location network performssaid reusability test by using said parameter.
 4. The location system ofclaim 2, wherein said parameter represents one of age and accuracy oflast known location information.
 5. The location system of claim 1,wherein said location network maintains privacy profile of the targetmobile terminal, uses the privacy profile to perform a privacy check onsaid location request and transmits said last known location informationif the privacy check indicates a favorable result.
 6. The locationsystem of claim 5, wherein said location network transmits anotification message to the target mobile terminal according to saidprivacy profile before transmitting said last known location informationto said communication terminal.
 7. The location system of claim 1,wherein said location network transmits a verification message to thetarget mobile terminal according to said privacy profile and transmitssaid last known location information to the communication terminal whenthe location system receives a verification report from the targetmobile terminal which indicates that the location request is verified bythe target mobile terminal.
 8. The location system of claim 1, whereinsaid communication terminal is a client terminal.
 9. The location systemof claim 1, wherein said communication terminal is a mobile terminalwhich represents one of said plurality of mobile terminals.
 10. Thelocation system of claim 9, wherein said location network is responsiveto said location request from one of said mobile terminals for producingcurrent location information of a target mobile terminal if the type oflocation information specifies current location information andtransmitting the current location information to said one mobileterminal and storing the last known location information in a memory aslast known location information of the target mobile terminal, andcopying last known location information of the target mobile terminalfrom the memory if said type of location information specifies lastknown location information and transmitting the copied information tosaid one mobile terminal.
 11. The location system of claim 1, whereinsaid location network comprises: a plurality of gateways for receivingsaid location request from said communication terminal, each of saidgateways storing last known location information of home mobileterminals, said location request further containing a parameter of lastknown location information; a plurality of registers associatedrespectively with said gateways; and a plurality of wireless networksconnected to said gateways for establishing wireless links to saidmobile terminals, each of said gateways being responsive to a locationrequest from said communication terminal specifying one of said homemobile terminals as a target mobile terminal, (a) transmitting a copy ofthe stored last known location information of the target mobile terminalto the communication terminal if the type of location information of thelocation request specifies last known location information and if saidparameter of last known location information is met by the stored lastknown location information, and (b) acquiring a node identifier from theassociated register if said parameter is not met by the stored lastknown location information, acquiring current location information ofthe target mobile terminal from one of said wireless networks specifiedby the acquired node identifier and transmitting the acquired currentlocation information to the communication terminal.
 12. The locationsystem of claim 11, wherein each of said gateways maintains privacyprofiles of the home mobile terminals, and wherein each of the gatewaystransmits said copy of stored last known location information if saidlocation request meets the privacy profile of the target mobileterminal.
 13. The location system of claim 11, wherein said locationnetwork further comprises a plurality of privacy profile registersassociated respectively with said gateways for storing privacy profilesof home mobile terminals of the associated gateway, each of saidgateways transmitting a request to the associated privacy profileregister in response to receipt of said location request for requestingthe associated register to make a decision as to whether the locationrequest meets the privacy profile of the target mobile terminal,receiving a report indicating said decision, and transmitting said copyof last known location information if said decision is favorable. 14.The location system of claim 1, wherein said location network comprises:a plurality of gateways for receiving said location request from saidcommunication terminal, said location request further containing aparameter of last known location information; a plurality of registersassociated respectively with said gateways; a plurality of wirelessnetworks connected to said gateways for establishing wireless links tosaid mobile terminals, each of said wireless networks storing last knownlocation information of home mobile terminals, each of said gatewaysbeing responsive to a location request from said communication terminalspecifying one of said home mobile terminals as a target mobileterminal, (a) acquiring a node identifier from the associated register,acquiring last known location information of the target mobile terminalfrom one of said wireless networks specified by the acquired nodeidentifier if the type of location information of the location requestspecifies last known location information and if said parameter of lastknown location information is met by the stored last known locationinformation, and (b) acquiring current location information of thetarget mobile terminal from said specified wireless network if saidparameter is not met by the stored location information and transmittingthe acquired current location information to the communication terminal.15. The location system of claim 1, wherein said location networkcomprises: a gateway including receive means for receiving a locationrequest from a communication terminal, said request specifying a targetmobile terminal and a type of location information; and a wirelessnetwork including: a memory; control means for receiving the locationrequest from said gateway and producing current location information ofthe target mobile terminal if the type of location information of thereceived request specifies current location information and storing theacquired current location information in said memory as last knownlocation information of the target mobile terminal, and reading thestored last known location information of the target mobile terminalfrom said memory if said type of location information specifies lastknown location information; and transmit means for transmitting, to saidgateway, a copy of the acquired current location information or a copyof the last known location information read from said memory, dependingon said type of last known location information, said gateway furtherincluding transmit means for repeating said copy of current locationinformation or last known location information to said communicationterminal.
 16. The location system of claim 15, wherein said locationrequest further contains a parameter of last known location information,and a privacy profile of said target mobile terminal is stored in saidmemory, wherein said control means includes reusability check means forperforming a reusability test by checking said parameter with the storedprivacy profile when said type of location information specifies lastknown location information and reading the stored last known locationinformation from said memory when said reusability test indicates afavorable result.
 17. The location system of claim 15, wherein saidprivacy profile indicates whether or not notification is required fornotifying that the target mobile terminal is being accessed, and whereinsaid control means further includes notification means for transmittinga notification message to said target mobile terminal prior to thetransmission of said last known location information to saidcommunication terminal if said privacy profile of said target mobileterminal requires notification.
 18. The location system of claim 15,wherein said privacy profile indicates whether or not the locationrequest is verified by the target mobile terminal, and wherein saidcontrol means further includes verification means for transmitting averification message to said target mobile terminal and receiving averification report from the target mobile terminal prior to thetransmission of said last known location information to said gateway ifsaid privacy profile of said target mobile terminal indicates thatverification by the target mobile terminal is required, and transmittingsaid copy of last known location information to said gateway if saidverification report indicates a favorable result.
 19. A location systemcomprising: a communication terminal (101) for transmitting a locationrequest specifying a target mobile terminal, a type of locationinformation, and a parameter of last known location information; agateway (102) for storing last known location information of home mobileterminals and privacy profiles of the mobile terminals; and a pluralityof wireless networks (103, 104) for establishing a wireless link tomobile terminals, said gateway (102) being responsive to said locationrequest for performing a reusability test by checking said parameterwith the privacy profile of the target mobile terminal if said typespecifies last known location information, acquiring a node identifierfrom an associated register and current location information of thetarget mobile terminal from one of said wireless networks specified bysaid node identifier if said reusability test indicates an unfavorableresult, transmitting the current location information from the gatewayto the communication terminal, and storing the current locationinformation in a memory as last known location information of saidtarget mobile terminal, said gateway transmitting a copy of last knownlocation information of the target mobile terminal to the communicationterminal if said reusability test indicates a favorable result.
 20. Alocation system comprising: a communication terminal (101) fortransmitting a location request specifying a target mobile terminal, atype of location information, and a parameter of last known locationinformation; a gateway (102); a register (106); and a plurality ofwireless networks (103, 104) for establishing a wireless link to mobileterminals and storing privacy profiles and location information of saidmobile terminals, said gateway (102) being responsive to said locationrequest for (a) acquiring a node identifier from said register (106) ifsaid type specifies last known location information, (b) authorizing oneof a plurality of wireless networks specified by the node identifier toperform a reusability test by checking said parameter with the privacyprofile of the target mobile terminal, (c) acquiring from currentlocation information of the target mobile terminal from said onewireless network, and storing the current location information in amemory, and (d) acquiring a copy of the last known location informationof the target mobile terminal from said one wireless network if saidreusability test indicates a favorable result or a copy of the currentlocation information if said reusability test indicates an unfavorableresult and transmitting the copy of the last known location informationor current location information to said communication terminal.
 21. Thelocation system of claim 20, wherein one of said mobile terminalstransmits a location request specifying a target mobile terminal, a typeof location information and a parameter of last known locationinformation, one of said wireless networks being responsive to alocation request from said one mobile terminal for (a) performing areusability test by checking said parameter with the privacy profile ofthe target mobile terminal if said type specifies last known locationinformation, (b) producing current location information of the targetmobile terminal if said reusability test indicates an unfavorableresult, (c) transmitting the current location information to therequesting mobile terminal, (d) storing the current location informationin a memory as last known location information of said target mobileterminal, and (e) transmitting a copy of last known location informationof the target mobile terminal to the requesting mobile terminal if saidreusability test indicates a favorable result.
 22. A location systemcomprising: a communication terminal (111) for transmitting a locationrequest specifying a target mobile terminal, a type of locationinformation, and a parameter of last known location information; a firstgateway (112); a second gateway (102) for storing last known locationinformation of home mobile terminals and privacy profiles of the mobileterminals; first and second registers (116, 106) respectively associatedwith said first and second gateways; and a plurality of wirelessnetworks (103, 104) for establishing a wireless link to mobileterminals, said first gateway (112) being responsive to said locationrequest from said communication terminal for acquiring a node identifierspecifying said second gateway from said first register (116), andtransmitting said location request to said second gateway (102); saidsecond gateway (102) being responsive to the location request from thefirst gateway for (a) performing a reusability test by checking saidparameter with the privacy profile of the target mobile terminal if saidtype of location information specifies last known location information,(b) acquiring a node identifier from said second register (106) andcurrent location information of the target mobile terminal from one ofsaid plurality of wireless networks specified by the node identifier ifsaid reusability test indicates an unfavorable result, (c) transmittingthe current location information to the communication terminal via thefirst gateway, (d) storing the current location information in a memoryas last known location information of said target mobile terminal, and(e) transmitting a copy of last known location information of the targetmobile terminal to the communication terminal via the first gateway(112) if said reusability test indicates a favorable result.
 23. Thelocation system of claim 22, further comprising a third gateway (122)which, when visited by said target mobile terminal, operates as arepeater node between said one wireless network (123, 124) and saidsecond gateway (102) for repeating said current location information.24. The location system of claim 19, further comprising a second gateway(112) which, when visited by said target mobile terminal, operates as arepeater node between said one wireless network (113, 114) and saidfirst gateway (102) for repeating said current location information. 25.The location system of claim 22, wherein said first gateway (112)operates as a repeater node between said second gateway (102) and saidone wireless network (103, 104) for repeating said current locationinformation.
 26. A location system comprising: a communication terminal(101) for transmitting a location request specifying a target mobileterminal, a type of location information, and a parameter of last knownlocation information; a gateway (102); a privacy profile register (107)for storing privacy profiles and location information of mobileterminals; a home location register (106); and a wireless network (103,104) for establishing a wireless link to said mobile terminals, saidgateway being responsive to said location request for (a) authorizingsaid privacy profile register to perform a reusability test by checkingsaid parameter with the privacy profile of the target mobile terminal ifsaid type specifies last known location information, (b) receiving areport of said reusability test from said privacy profile register, (c)acquiring a node identifier from said home location register and currentlocation information of the target mobile terminal from one of aplurality of wireless networks specified by said node identifier if saidreport indicates that said reusability test indicates an unfavorableresult, (d) transmitting the current location information from thegateway to the communication terminal, (e) storing the current locationinformation in a memory of said privacy profile register as last knownlocation information of said target mobile terminal, and (f)transmitting a copy of last known location information of the targetmobile terminal to the communication terminal if said report indicatesthat said reusability test indicates a favorable result.
 27. A locationsystem comprising: a communication terminal (101) for transmitting alocation request specifying a target mobile terminal and a type oflocation information; a gateway (102) for storing last known locationinformation of home mobile terminals; a home location register (106); aprivacy profile register (107) for storing privacy profiles of themobile terminals; and a plurality of wireless networks (103, 104) forestablishing a wireless link to mobile terminals, said gateway beingresponsive to said location request for (a) authorizing said privacyprofile register to perform a privacy check with the privacy profile ofthe target mobile terminal if said type specifies last known locationinformation, (b) receiving a report of the privacy check from saidprivacy profile register, (c) acquiring a node identifier from said homelocation register and current location information of the target mobileterminal from one of said wireless networks specified by said nodeidentifier if said report indicates that said privacy check indicates anunfavorable result, (d) transmitting the current location informationfrom the gateway to the communication terminal, (e) storing the currentlocation information in a memory as last known location information ofsaid target mobile terminal, and (f) transmitting a copy of last knownlocation information of the target mobile terminal to the communicationterminal if said report indicates that said privacy check indicates afavorable result.
 28. A location system comprising: a communicationterminal (111) for transmitting a location request specifying a targetmobile terminal, a type of location information, and a parameter of lastknown location information; first and second gateways (112, 102); firstand second home location registers (116, 106) respectively associatedwith said first and second gateways; a privacy profile register (107)associated with said second gateway (102) for storing last knownlocation information of home mobile terminals and privacy profiles ofthe mobile terminals; and a plurality of wireless networks (103, 104)for establishing a wireless link to mobile terminals, said first gateway(112) being responsive to said location request from said communicationterminal for acquiring a node identifier specifying said second gateway(102) from said first home location register (116), and transmittingsaid location request to said second gateway (102); said second gateway(102) being responsive to the location request from the first gateway(112) for authorizing the privacy profile register (107) to perform areusability test by checking said parameter with the privacy profile ofthe target mobile terminal if said type of location informationspecifies last known location information and produce a reportindicating a result of the reusability test, said second gateway (102)being responsive to said report for acquiring a node identifier fromsaid second home location register (106) and current locationinformation of the target mobile terminal from one of said plurality ofwireless networks specified by the node identifier if said reportindicates that the result of the reusability test is unfavorable,transmitting the current location information to the communicationterminal via the first gateway (112), and storing the current locationinformation in a memory as last known location information of saidtarget mobile terminal, and transmitting a copy of last known locationinformation of the target mobile terminal to the communication terminalvia the first gateway (112) if said report indicates that the result ofthe reusability test is favorable.
 29. A location system comprising: acommunication terminal (111) for transmitting a location requestspecifying a target mobile terminal, a type of location information, anda parameter of last known location information; a first gateway (112); asecond gateway (102) for storing last known location information of homemobile terminals; first and second home location registers (116, 106)respectively associated with said first and second gateways; a privacyprofile register (107) associated with said second gateway (102) forstoring privacy profiles of the mobile terminals; and a plurality ofwireless networks (103, 104) for establishing a wireless link to mobileterminals, said first gateway (112) being responsive to said locationrequest from said communication terminal for acquiring a node identifierspecifying said second gateway (102) from said first home locationregister (116), and transmitting said location request to said secondgateway (102); said second gateway (102) being responsive to thelocation request from the first gateway (112) for authorizing theprivacy profile register (107) to perform a privacy check with theprivacy profile of the target mobile terminal to produce a report of theprivacy check, said second gateway (102) being responsive to said reportfor performing a reusability test by checking said parameter with theprivacy profile of the target mobile terminal if said type of locationinformation specifies last known location information and if the resultof said privacy check is favorable, said second gateway (102) acquiringa node identifier from said second home location register (106) andcurrent location information of the target mobile terminal from one ofsaid plurality of wireless networks specified by the node identifier ifsaid reusability test indicates an unfavorable result, transmitting thecurrent location information to the communication terminal via the firstgateway (112), and storing the current location information in a memoryas last known location information of said target mobile terminal, andtransmitting a copy of last known location information of the targetmobile terminal to the communication terminal via the first gateway(112) if said reusability test indicates a favorable result.
 30. Thelocation system of claim 28, further comprising a third gateway (122)which, when visited by said target mobile terminal, operates as arepeater node between said second gateway (102) and said one wirelessnetwork (123, 124) for repeating said current location information. 31.The location system of claim 29, further comprising a third gateway(122) which, when visited by said target mobile terminal, operates as arepeater node between said second gateway (102) and said one wirelessnetwork (123, 124) for repeating said current location information. 32.The location system of claim 26, further comprising a second gateway(112) which, when visited by said target mobile terminal, operates as arepeater node between said first gateway (102) and said one wirelessnetwork (113, 114) for repeating said current location information. 33.The location system of claim 27, further comprising a second gateway(112) which, when visited by said target mobile terminal, operates as arepeater node between said first gateway (102) and said one wirelessnetwork (113, 114) for repeating said current location information. 34.The location system of claim 28, wherein said first gateway (112)operates as a repeater node between said second gateway (102) and saidone wireless network (113, 114) for repeating said current locationinformation.
 35. The location system of claim 28, wherein said firstgateway (112) operates as a repeater node between said second gateway(102) and said one wireless network (113, 114) for repeating saidcurrent location information.
 36. A gateway for operating with alocation network to which mobile terminals are wirelessly connected,comprising: receive means for receiving a location request from acommunication terminal, said request specifying a target mobile terminaland a type of location information; a memory; control means foracquiring current location information of the target mobile terminalfrom said location network if the type of location information of thereceived request specifies current location information and storing theacquired current location information in said memory as last knownlocation information of the target mobile terminal, and reading thestored last known location information of the target mobile terminalfrom said memory if said type of location information specifies lastknown location information; and transmit means for transmitting, to saidcommunication terminal, a copy of the acquired current locationinformation or a copy of the last known location information read fromsaid memory, depending on said type of last known location information.37. The gateway of claim 36, wherein said location request furthercontains a parameter of last known location information, and a privacyprofile of said target mobile terminal is stored in said memory, whereinsaid control means includes reusability check means for performing areusability test by checking said parameter with the stored privacyprofile when said type of location information specifies last knownlocation information and reading the stored last known locationinformation from said memory when said reusability test indicates afavorable result.
 38. The gateway of claim 36, wherein said privacyprofile indicates whether or not notification is required for notifyingthat the target mobile terminal is being accessed, and wherein saidcontrol means further includes notification means for transmitting anotification message to said target mobile terminal prior to thetransmission of said last known location information to saidcommunication terminal if said privacy profile of said target mobileterminal requires notification.
 39. The gateway of claim 36, whereinsaid privacy profile indicates whether or not the location request isverified by the target mobile terminal, and wherein said control meansfurther includes verification means for transmitting a verificationmessage to said target mobile terminal and receiving a verificationreport from the target mobile terminal prior to the transmission of saidlast known location information to said communication terminal if saidprivacy profile of said target mobile terminal indicates thatverification by the target mobile terminal is required, and transmittingsaid copy of last known location information to said communicationterminal if said verification report indicates a favorable result.
 40. Alocation method comprising the steps of: a) transmitting a locationrequest from a communication terminal, said request specifying a targetmobile terminal and a type of location information; b) receiving thelocation request at a location network; c) producing current locationinformation of the target mobile terminal and transmitting the currentlocation information from the location network to said communicationterminal if the type of location information of the received requestspecifies current location information; d) storing the current locationinformation in a memory as last known location information of the targetmobile terminal; and e) copying the stored last known locationinformation of the target mobile terminal from said memory if said typeof location information specifies last known location information andtransmitting the copied information from the location network to saidcommunication terminal.
 41. The location method of claim 40, whereinstep (e) comprises the steps of performing a reusability test on saidstored last known location information and transmitting said last knownlocation information if said reusability test indicates a favorableresult.
 42. The location method of claim 41, wherein step (e) furthercomprises the steps of: if said reusability test indicates anunfavorable result, producing current location information of the targetmobile terminal and transmitting the current location information fromthe location network to said communication terminal; and storing thecurrent location information in said memory as last known locationinformation of the target mobile terminal.
 43. The location method ofclaim 41, wherein said location request contains a requested age of lastknown location information, and wherein step (e) comprises the steps ofperforming said reusability test by using said requested age andtransmitting said copy of the stored last known location information ifthe stored last known location information meets said requested age. 44.The location method of claim 41, wherein said location request containsa requested age of last known location information, and wherein step (e)comprises the steps of: performing said reusability test by using saidrequested age; producing current location information of the targetmobile terminal and transmitting the current location information fromthe location network to said communication terminal if the type oflocation information of the received request specifies current locationinformation if said reusability test indicates that the stored lastknown information fails to meet the requested age; and storing thecurrent location information in said memory as last known locationinformation of the target mobile terminal.
 45. The location method ofclaim 40, wherein said location network maintains privacy profile of thetarget mobile terminal, and wherein step (e) comprises the steps oftransmitting a notification message to the target mobile terminalaccording to said privacy profile, before transmitting said last knownlocation information to the communication terminal.
 46. The locationmethod of claim 40, wherein said location network maintains privacyprofile of the target mobile terminal, and wherein step (e) comprisesthe steps of transmitting a verification message to the target mobileterminal according to said privacy profile and transmitting said lastknown location information if a verification report from the targetmobile terminal indicates that the location request is verified by thetarget mobile terminal.
 47. The location method of claim 40, whereinsaid location network produces and transmits current locationinformation of said target mobile terminal to said communicationterminal if the stored location information of the target mobileterminal is not available and said type of location informationindicates that current location information can be used instead of lastknown location information.
 48. The location method of claim 40, whereinsaid communication terminal is a client terminal.
 49. The locationmethod of claim 40, wherein said communication terminal is a mobileterminal which represents one of said plurality of mobile terminals. 50.The location method of claim 48, further comprising the steps of:transmitting a location request from one of said mobile terminals, saidrequest specifying a target mobile terminal and a type of locationinformation; receiving said location request at said location network;producing current location information of a target mobile terminal andtransmitting the current location information from said location networkto said one mobile terminal if the type of location informationspecifies current location information; storing the current locationinformation in a memory as last known location information of the targetmobile terminal; and copying the last known location information of thetarget mobile terminal from said memory if said type of locationinformation specifies last known location information and transmittingthe copied information from said location network to said one mobileterminal.
 51. The location method of claim 40, wherein step (b)comprises the steps of performing a privacy check of the locationrequest and performing steps (c) to (e) if said privacy check indicatesa favorable result.
 52. A method of operating a gateway with a locationnetwork, comprising the steps of: a) receiving a location request from acommunication terminal, said request specifying a target mobile terminaland a type of location information; b) acquiring current locationinformation of the target mobile terminal from said location network andtransmitting the current location information to said communicationterminal if the type of location information of the received requestspecifies current location information; c) storing the current locationinformation in a memory as last known location information of the targetmobile terminal; and d) transmitting a copy of the stored last knownlocation information of the target mobile terminal to said communicationterminal if said type of location information specifies last knownlocation information.
 53. The method of claim 52, wherein step (d)comprises the steps of performing a reusability test on said stored lastknown location information and transmitting said last known locationinformation if said reusability test indicates a favorable result. 54.The method of claim 53, wherein step (d) further comprises the steps of:if said reusability test indicates an unfavorable result, producingcurrent location information of the target mobile terminal andtransmitting the current location information from the location networkto said communication terminal; and storing the current locationinformation in said memory as last known location information of thetarget mobile terminal.
 55. The method of claim 53, wherein saidlocation request contains a parameter of last known locationinformation, and wherein step (d) comprises the steps of performing saidreusability test by using said parameter and transmitting said lastknown location information if the reusability test indicates a favorableresult.
 56. The method of claim 55, wherein said parameter representsone of age and accuracy of last known location information.
 57. Themethod of claim 52, wherein said location network maintains privacyprofile of the target mobile terminal, and wherein step (d) comprisesthe step of transmitting a notification message to the target mobileterminal according to said privacy profile before said last knownlocation information is transmitted to the communication terminal. 58.The method of claim 52, wherein said location network maintains privacyprofile of the target mobile terminal, and wherein step (d) comprisesthe steps of transmitting a verification message to the target mobileterminal according to said privacy profile and transmitting said lastknown location information if a verification report from the targetmobile terminal indicates that the location request is verified by thetarget mobile terminal.
 59. The method of claim 52, wherein step (a)comprises the steps of performing a privacy check of the locationrequest and performing steps (b) to (d) if said privacy check indicatesa favorable result.
 60. A communication terminal comprising: transmitmeans for transmitting a location request to a location system in whichlast known location information of mobile terminals are stored, saidlocation request specifying a target mobile terminal and a type of lastknown location information; and receive means for receiving from saidlocation system a copy of current location information of the targetmobile terminal if said type specifies current location information or acopy of last known location information of the target mobile terminal ifsaid type specifies last known location information.
 61. Thecommunication terminal of claim 60, wherein said location requestfurther specifies a parameter of last known location information. 62.The communication terminal of claim 61, wherein said parameterrepresents one of age and accuracy of stored last known locationinformation.
 63. The communication terminal of claim 60, furthercomprising: a memory for storing the current location informationreceived from said location system as last known location information ofsaid target mobile terminal; and control means performing a reusabilitytest on the last location information stored in said memory in responseto a request from a user, displaying the last known location informationif the reusability test indicates a favorable result.
 64. A computerreadable storage medium storing a program of operating a gateway with alocation network, said program comprising the steps of: a) receiving alocation request from a communication terminal, said request specifyinga target mobile terminal and a type of location information; b)acquiring current location information of the target mobile terminalfrom said location network and transmitting the current locationinformation to said communication terminal if the type of locationinformation of the received request specifies current locationinformation; c) storing the current location information in a memory aslast known location information of the target mobile terminal; and d)transmitting a copy of the stored last known location information of thetarget mobile terminal to said communication terminal if said type oflocation information specifies last known location information.
 65. Thecomputer readable storage medium of claim 64, wherein step (d) comprisesthe steps of performing a reusability test on said stored last knownlocation information and transmitting said last known locationinformation if said reusability test indicates a favorable result. 66.The computer readable storage medium of claim 64, wherein step (d)further comprises the steps of: if said reusability test indicates anunfavorable result, producing current location information of the targetmobile terminal and transmitting the current location information fromthe location network to said communication terminal; and storing thecurrent location information in said memory as last known locationinformation of the target mobile terminal.
 67. The computer readablestorage medium of claim 64, wherein said location request contains aparameter of last known location information, and wherein step (d)comprises the steps of performing said reusability test by using saidparameter and transmitting said last known location information if thereusability test indicates a favorable result.
 68. The computer readablestorage medium of claim 67, wherein said parameter represents one of ageand accuracy of last known location information.
 69. The computerreadable storage medium of claim 64, wherein said location networkmaintains privacy profile of the target mobile terminal, and whereinstep (d) comprises the step of transmitting a notification message tothe target mobile terminal according to said privacy profile before saidlast known location information is transmitted to the communicationterminal.
 70. The computer readable storage medium of claim 64, whereinsaid location network maintains privacy profile of the target mobileterminal, and wherein step (d) comprises the steps of transmitting averification message to the target mobile terminal according to saidprivacy profile and transmitting said last known location information ifa verification report from the target mobile terminal indicates that thelocation request is verified by the target mobile terminal.
 71. Thecomputer readable storage medium of claim 64, wherein step (a) comprisesthe steps of performing a privacy check of the location request andperforming steps (b) to (d) if said privacy check indicates a favorableresult.